The present invention relates to a PGA socket that is used when a PGA (Pin Grid Array) package provided with a plurality of pins in a grid array fashion is connected to a printed circuit board and the like.
In a desktop computer etc., a PGA socket 100 shown in FIG. 6, for example, has been used when a PGA package such as CPU (Central Processing Unit) provided with a plurality of pins in a grid array fashion is connected to a printed circuit board and the like.
The conventional PGA socket 100 shown in FIG. 6 comprises a base housing 101 formed with contact holes (not shown) in a grid array fashion, contacts (not shown) held in the contact holes of the base housing 101, a cover housing 102 formed with through holes 102a in a grid array fashion through which pins of a PGA package can be inserted and a lever 103 as a sliding mechanism for sliding the cover housing 102 over the base housing 101. The lever 103 is in an L-like shape including a handle portion 103a, which is gripped and rotated in a vertical direction by operators. When the lever 103 is rotated in a vertical direction in the PGA socket 100, the cover housing 102 is slid over the base housing 101 and the pins of the PGA package and the contacts are in contact with each other. As a result, the PGA package and a printed circuit board on which the PGA socket is mounted are electrically connected to each other.
Prices of desktop computers including the above-mentioned conventional PGA sockets have been reduced. For realizing a more reduced price, it is required to reduce unit prices of parts for instance the PGA sockets. However, the unit price of the above-mentioned conventional PGA socket 100 was not low enough to satisfy the requirement. In the above-mentioned conventional PGA socket 100, not so strong force is needed when the cover housing 102 is slid over the base housing 101. Therefore, when a PGA socket of which unit price is low is provided, it is desirable that the PGA socket does not need so strong force to slide a cover housing over a base housing as the conventional PGA socket 100.
It is an object of the present invention to provide a PGA socket of low unit price capable of sliding a cover housing over a base housing with a small force.
A PGA socket of the present invention comprises a base housing formed with a large number of contact holes in a grid array fashion, a cover housing located to overlap the base housing and formed with a large number of through holes in a grid array fashion through which pins of a PGA package can be inserted, a sliding mechanism for sliding the cover housing over the base housing, and a plurality of contacts held in the contact holes of the base housing and being in contact with the pins of the PGA package by slide operation of the cover housing caused by the sliding mechanism, wherein the sliding mechanism includes a rotatable operating portion having a step on an outer surface in a diametrical direction and a press-fitting portion for press-fitting the cover housing with rotation of the operating portion in a direction of sliding of the cover housing over the base housing.
According to the PGA socket having the above-mentioned structure, an operating tool (a tool used for sliding a cover housing over a base housing) is fitted in the step provided on the outer surface of the operating portion of the sliding mechanism in a diametrical direction and then the operating tool is rotated about a fitting portion with the operating portion. The operating portion may be thereby rotated with a small force according to a length of the operating tool to slide the cover housing over the base housing. Since the sliding mechanism is capable of sliding the cover housing over the base housing only with the operating portion and the press-fitting portion, it is unnecessary to provide a lever. This enables reduction of the unit price of the PGA socket by a price of the lever. Further, since the sliding mechanism does not have an equivalent to the handle portion 103a of the lever 103 of the conventional PGA socket 100, it is possible to locate components in a space in which the handle portion 103a was located. As a result, miniaturization of various kinds of equipments such as personal computers including the PGA sockets may be realized.
In the above-mentioned PGA socket, the step has a concavity with a boundary line dividing the step into a rectangular shape on the surface of the operating portion. According to the PGA socket having this structure, screwdrivers and the like that are mostly available at home and offices may be used as an operating tool. As a result, reduction of prices of various equipments including PGA sockets may be realized since it is unnecessary to prepare special purpose tools.